Tommy Tuberville followed up his first signature win at Texas Tech — last year’s upset of No. 1 Oklahoma — with a five-game losing streak.

Why should this year be any different after last week’s upset of fifth-ranked West Virginia?

“We’ve got six games left this time,” Tuberville said, dry as West Texas.

Here’s the real difference as the Raiders try to avoid a similar slump, starting Saturday in Fort Worth against TCU: Tech can, in Tuberville’s words, “play some defense,” which, as understatement goes, ranks up there with “Houston, we have a problem,” and “This may hurt a little.”

The Raiders were ranked 114th out of 120 teams in total defense last year. They’re now fourth. They’ve risen so far, so fast, it should have given them the bends.

The obvious question is, how did it happen? How did Tech go from the worst run defense these eyes have ever witnessed to a defense that effectively shut down college football’s most explosive offense last week in a 49-14 win?

Once we might have expected as much. Like, three years ago, when Tuberville was hired. He made a reputation as a defensive coordinator. He also had one for signature wins. At Ole Miss and Auburn, he played teams from the AP top 5 seven times. He won four. They weren’t shootouts. The most points his defenses gave up in any of the wins was 20, against No. 1 Florida in 2001. The fewest was nine, against No. 5 LSU in 2004.

Tech hadn’t won many games on defense the decade or so before he got there in 2010. It’s not in Mike Leach’s DNA. The Pirate put all his time and best people into his offense, and, for the most part, it worked.

But when Tuberville arrived and tried to install the kind of defense he was accustomed to, it was a mismatch.

“Obviously there’d been no emphasis on defense whatsoever,” he said of the previous regime. “The personnel weren’t suited to us. We were moving linebackers to the defensive line. We had a few players, but you just can’t have a few.”

Tuberville has had a few defensive coordinators, too. His first, James Willis, left after one season and just ahead of domestic violence charges. His successor, Chad Glasgow, from TCU, made a quick U-turn for Fort Worth.

Next up: Art Kaufman, Tuberville’s defensive coordinator at Ole Miss.

Kaufman didn’t hit town with a vastly different scheme. Four-man front, control your gap. The personnel didn’t change much, either. The starters, led by senior safeties Cody Davis and D.J. Johnson and junior defensive end Kerry Hyder, are essentially the same. A mixture of junior college transfers and redshirt freshmen added much-needed speed and depth to a unit depleted by injuries last year.

What Kaufman brought to the table, basically, was patience.

“I coached defense a long time, and sometimes you get impatient,” Tuberville said. “Sometimes you think you’ve got to out-coach the other guy. Art likes to keep it simple. We don’t make a lot of mental mistakes.

Never underestimate wounded pride, either. The Raiders’ defensive players chafed at their previous reputation. A few guaranteed change, and they’ve delivered. Dana Holgorsen said it wasn’t the scheme that beat West Virginia. “They just played harder,” the Mountaineers’ coach said.

Against West Virginia, which hung 70 on Baylor and beat Texas, 48-45, in Austin, Tech’s defensive line was left on its own to contain Geno Smith. The other seven dropped into coverage. Tech produced no turnovers or sacks. But Smith, the early Heisman favorite after posting unworldly numbers and performances, was just OK against Tech, throwing for 275 yards and a touchdown.

Can the Raiders’ new headliner defense keep it up? The road gets no easier this week in Fort Worth, where Gary Patterson has a pretty fair defensive reputation of his own. Next week: Manhattan, Kan., and Bill Snyder’s extremely well-coached Kansas State team.

From that point it’s Texas and Kansas at home, Oklahoma State on the road and Baylor in JerryWorld.

Could Tech follow up a big win with another collapse?

“You never know about matchups in college football,” Tuberville said. “You just don’t know.

“There are so many good athletes on offense in this conference.”

Fortunately for Tuberville, he officially has a defense, and just in time. I was beginning to think he’d left it at Auburn.